CN106955592A - The urea pyrolysis ammonia structures and methods of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate can be reduced - Google Patents
The urea pyrolysis ammonia structures and methods of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate can be reduced Download PDFInfo
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- CN106955592A CN106955592A CN201710168527.9A CN201710168527A CN106955592A CN 106955592 A CN106955592 A CN 106955592A CN 201710168527 A CN201710168527 A CN 201710168527A CN 106955592 A CN106955592 A CN 106955592A
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- flue gas
- ammonia
- pyrolysis
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- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 title claims abstract description 66
- 239000004202 carbamide Substances 0.000 title claims abstract description 66
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical group N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 title claims abstract description 62
- AKEJUJNQAAGONA-UHFFFAOYSA-N sulfur trioxide Chemical compound O=S(=O)=O AKEJUJNQAAGONA-UHFFFAOYSA-N 0.000 title claims abstract description 57
- 238000000197 pyrolysis Methods 0.000 title claims abstract description 56
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 title claims abstract description 48
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 32
- 238000000034 method Methods 0.000 title claims abstract description 13
- 239000003546 flue gas Substances 0.000 claims abstract description 75
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims abstract description 74
- 239000007789 gas Substances 0.000 claims abstract description 68
- 239000003054 catalyst Substances 0.000 claims abstract description 60
- 238000010790 dilution Methods 0.000 claims abstract description 16
- 239000012895 dilution Substances 0.000 claims abstract description 16
- 238000005507 spraying Methods 0.000 claims abstract description 14
- 239000000779 smoke Substances 0.000 claims abstract description 9
- 239000003517 fume Substances 0.000 claims abstract description 5
- 239000007788 liquid Substances 0.000 claims description 33
- 229910021529 ammonia Inorganic materials 0.000 claims description 20
- 239000003085 diluting agent Substances 0.000 claims description 18
- 238000006722 reduction reaction Methods 0.000 claims description 16
- 229910000069 nitrogen hydride Inorganic materials 0.000 claims description 12
- 239000003638 chemical reducing agent Substances 0.000 claims description 10
- 239000000243 solution Substances 0.000 claims description 8
- 235000019504 cigarettes Nutrition 0.000 claims description 6
- 239000007921 spray Substances 0.000 claims description 6
- 230000003068 static effect Effects 0.000 claims description 5
- 239000002245 particle Substances 0.000 claims description 3
- 229920000642 polymer Polymers 0.000 claims description 2
- 210000002700 urine Anatomy 0.000 claims 1
- 230000008021 deposition Effects 0.000 abstract description 5
- WWILHZQYNPQALT-UHFFFAOYSA-N 2-methyl-2-morpholin-4-ylpropanal Chemical compound O=CC(C)(C)N1CCOCC1 WWILHZQYNPQALT-UHFFFAOYSA-N 0.000 abstract description 4
- 238000011144 upstream manufacturing Methods 0.000 abstract description 3
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 abstract description 2
- 229910052921 ammonium sulfate Inorganic materials 0.000 abstract description 2
- 235000011130 ammonium sulphate Nutrition 0.000 abstract description 2
- 230000003197 catalytic effect Effects 0.000 abstract description 2
- 230000009467 reduction Effects 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 239000003245 coal Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000000889 atomisation Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 108700018263 Brassica oleracea SCR Proteins 0.000 description 1
- 240000002853 Nelumbo nucifera Species 0.000 description 1
- 235000006508 Nelumbo nucifera Nutrition 0.000 description 1
- 235000006510 Nelumbo pentapetala Nutrition 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000010531 catalytic reduction reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 150000001875 compounds Chemical group 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000035800 maturation Effects 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/90—Injecting reactants
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/8621—Removing nitrogen compounds
- B01D53/8625—Nitrogen oxides
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
- C01C1/00—Ammonia; Compounds thereof
- C01C1/02—Preparation, purification or separation of ammonia
- C01C1/08—Preparation of ammonia from nitrogenous organic substances
- C01C1/086—Preparation of ammonia from nitrogenous organic substances from urea
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
- B01D2251/2062—Ammonia
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2258/00—Sources of waste gases
- B01D2258/02—Other waste gases
- B01D2258/0283—Flue gases
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
- Y02P20/129—Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Abstract
Present invention offer is a kind of to reduce the urea pyrolysis ammonia structures and methods of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate.Atomizing lance is arranged in pyrolysis chamber；Pyrolysis chamber's gas vent is connected with ammonia-spraying grid；Flue gas heat-exchange unit is arranged between first floor catalyst and second layer catalyst, and the smoke inlet of flue gas heat-exchange unit is communicated with first floor catalyst exhanst gas outlet, and exhanst gas outlet is communicated with second layer catalyst smoke inlet；The outlet of flue gas heat-exchange unit heat transferring medium is connected with pyrolysis chamber gas access, heat transferring medium entrance and dilution air outlet；Electric heater is arranged between the outlet of flue gas heat-exchange unit heat transferring medium and pyrolysis chamber gas access.Present invention utilizes fume afterheat, conventional urea pyrolysis cost is reduced, while being lowered into the flue-gas temperature of second layer catalyst, second layer catalyst and the below SO of catalytic unit is reduced2/SO3Conversion ratio, reduces SO3Growing amount, effectively alleviate the deposition problems of upstream device ammonium sulfate and ammonium hydrogen sulfate.
Description
Technical field
The urea pyrolysis ammonia of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate is reduced the present invention relates to a kind of
Structures and methods, belong to coal fired power plant SCR denitrating flue gas field.
Background technology
SCR（Selective Catalytic Reduction, SCR）Gas denitrifying technology is because of its denitration
Efficiency high, technology maturation, it has also become the one preferred technique of Large-scale fire-electricity unit denitration.Its know-why is that reduction is sprayed into flue gas
Agent NH3, harmless N is generated with the NOx reactions in flue gas under catalyst action2And H2O.SCR gas denitrifying technology engineer applieds
One of key be reducing agent preparation, such as Application No. 201310542654.2 Chinese patent, present domestic and international application
Reducing agent mainly has liquefied ammonia, ammoniacal liquor, three kinds of urea, but no matter which kind of reducing agent is required to using outside heat by liquid or with it
The ammonia that his compound form is present changes into ammonia, and how to reduce the consumption of this portion of energy turns into reducing agent Study on Preparation
Hot issue.
Also generally existing ammonium hydrogen sulfate to SCR denitration system（ABS）The problem of deposition, ABS is not complete by reactor outlet
The NH of full response3(the escaping of ammonia) and the SO in flue gas3With generating under certain condition, ABS under liquid has corrosivity and viscous
Property, harm catalyst, air preheater and follow-up equipment.As coal unit SCR equipment for denitrifying flue gas puts into operation the increase of time and super
The implementation of low emission transformation, ABS deposition problems progressively highlight, are mainly manifested in air preheater resistance and are significantly increased, seriously
Influence the safe and stable operation of unit.
Meanwhile, catalyst also has certain scope and requirement to running temperature in coal unit SCR denitration system, and cigarette temperature is low
In minimum continuous running temperature（MOT）NH4HSO can be caused4Generate and blocking catalyst internal-response micropore, cause catalyst to lose
It is living.Therefore, in actual denitration operation, in order to ensure the activity of catalyst, denitrification apparatus should operate in minimum company steadily in the long term
It is more than reforwarding row cigarette temperature；However, current country's unit generally existing rate of load condensate is low, denitrification apparatus entrance flue gas temperature is low, low negative
Under lotus operating condition denitrification apparatus put into operation problem also more protrude.
Correlative study shows：The minimum continuous running temperature of SCR equipment for denitrifying flue gas mainly with inlet flue gas condition
NH3Concentration and SO3Concentration is relevant, with SO3And NH3The increase of concentration and raise, but due to major part after first floor catalyst
NH3It is consumed, for the second layer and with rear catalyst, required minimum continuous running temperature is significantly reduced, fits
When the reduction second layer and later layer catalyst inlet flue-gas temperature will not influence on the generation that denitrification apparatus full load is run；Separately
Outside, SO2/SO3Conversion it is main by reaction temperature and NH3The influence of concentration.Flue-gas temperature is higher, SO2/SO3Conversion ratio get over
It is high；NH3 concentration is higher, SO2/SO3Conversion ratio it is lower.For SCR flue gas denitrification systems, due to first floor catalyst inlet NH3It is dense
Spend higher, the SO of generation2/SO3Conversion it is few, but after first floor catalyst, most NH3It is consumed, the second level and below
The NH3 concentration of catalyst is relatively low, is SO2/SO3The main generation area of conversion, if SCR equipment for denitrifying flue gas can be controlled rationally
Flue-gas temperature after first floor catalyst, for reduction SO3Generation have important influence.
Therefore, how SCR multi-layer catalysts SO is correctly utilized2/SO3Transformation rule and denitration rule, will reduce SO3Generation,
The preparation for reducing the escaping of ammonia and reducing agent is joined together, and while ammonia cost processed is reduced, further alleviates SCR upstream devices
ABS phenomenons, a new focus as reducing agent preparation field research.
The content of the invention
It is an object of the invention to overcome above shortcomings in the prior art, and provide a kind of reasonable in design
The urea pyrolysis ammonia structures and methods of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate can be reduced, are ensureing denitration system
While system Effec-tive Function, cost of energy prepared by reducing agent is reduced, SO is reduced2/SO3Conversion ratio, mitigates ABS depositional phenomenons.
The present invention the used technical scheme that solves the above problems is：One kind can reduce SCR denitration system SO2/SO3Conversion
The urea pyrolysis ammonia structure of rate, including urea liquid dissolving tank, filter, urea liquid transfer pump, metered dispensing unit,
Atomizing lance, pyrolysis chamber and SCR reactors；Urea liquid dissolving tank, filter, urea liquid transfer pump, metering distribution dress
Put, atomizing lance is sequentially communicated；Atomizing lance is arranged in pyrolysis chamber；Ammonia-spraying grid, static state are disposed with SCR reactors
Blender, flow straightening grid, first floor catalyst, second layer catalyst and third layer catalyst；The gas vent of pyrolysis chamber and spray ammonia
Grid is connected；It is characterized in that：Also include flue gas heat-exchange unit, electric heater and dilution air；Flue gas heat-exchange unit is arranged on the first floor
Between catalyst and second layer catalyst, the smoke inlet of flue gas heat-exchange unit is communicated with the exhanst gas outlet of first floor catalyst, flue gas
The exhanst gas outlet of heat exchanger is communicated with the smoke inlet of second layer catalyst；The heat transferring medium outlet of flue gas heat-exchange unit and pyrolysis chamber
Gas access is connected, the outlet of heat transferring medium entrance and dilution air；Electric heater is arranged on flue gas heat-exchange unit heat exchange Jie
Matter is exported between pyrolysis chamber gas access.
Dilution air of the present invention is two, and two dilution airs are arranged in parallel.
Flue gas heat-exchange unit of the present invention uses pipe heat exchanger, and heat exchanger tube uses finned tube.
Filter of the present invention is two, and two filters are arranged in parallel.
Urea liquid transfer pump of the present invention is two, and two urea liquid transfer pumps are arranged in parallel.
It is a kind of to reduce the urea pyrolysis ammonia method of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate, its feature
It is：Carried out using described urea pyrolysis ammonia structure；Flue gas enters from the smoke inlet of SCR reactors；Urea liquid is stored up
After concentration of polymer solution filters for 30%~50% urea liquid through filter in tank, meter is pumped into by urea liquid supply
Measure distributor and carry out metering distribution, atomizing lance is then fed into, atomizing lance is injected urea solution into pyrolysis chamber, with high temperature
Boil-off gas be sufficiently mixed, be pyrolyzed, form the mixed gas of ammonia, air and vapor；Mixed gas is gone out by the gas of pyrolysis chamber
Mouth enters ammonia-spraying grid, and mixed gas is injected in the flue gas of SCR reactors by ammonia-spraying grid, and mixed gas is with flue gas by quiet
Enter first floor catalyst after the mixing of state blender and carry out reduction reaction；Flue gas after reduction reaction is dropped by flue gas heat-exchange unit temperature
Second layer catalyst is sequentially entered after low 20~50 DEG C and third layer catalyst carries out reduction reaction, finally from SCR reactors
Exhanst gas outlet is discharged；
Dilution air provides diluent gas, and diluent gas is used as the cigarette in heat transferring medium, with SCR reactors into flue gas heat-exchange unit
Gas carries out heat exchange, and diluent gas is heated using fume afterheat, and heated diluent gas further adds by electric heater again
Heat is to 350~650 DEG C, and subsequently into pyrolysis chamber, the boil-off gas as pyrolysis urea liquid, the urea sprayed into atomizing lance is molten
Liquid particle is sufficiently mixed, and urea is decomposed, and prepares reducing agent NH3。
Diluent gas of the present invention is surrounding air.
Diluent gas of the present invention again by electric heater be further heated to 350 DEG C, 400 DEG C, 450 DEG C, 500
DEG C, 550 DEG C, 600 DEG C or 650 DEG C.
Flue gas after reduction reaction of the present invention by flue gas heat-exchange unit temperature reduce by 20 DEG C, 25 DEG C, 30 DEG C, 35 DEG C, 40 DEG C,
45 DEG C or 50 DEG C.
Metered dispensing unit of the present invention controls to spray into the urea amount of pyrolysis chamber as needed.
The present invention compared with prior art, with advantages below and effect：Because the present invention passes through in SCR denitration device head
Flue gas heat-exchange unit is set between layer catalyst and second layer catalyst, fume afterheat is make use of, reduces conventional urea and be pyrolyzed into
This；The flue-gas temperature of second layer catalyst is lowered into simultaneously, reduces second layer catalyst and the below SO of catalytic unit2/SO3
Conversion ratio, reduces SO3Growing amount, effectively alleviate the deposition problems of upstream device ammonium sulfate and ammonium hydrogen sulfate.
Brief description of the drawings
Fig. 1 is that the embodiment of the present invention can reduce the urea pyrolysis system of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate
The structural representation of ammonia structure.
Embodiment
Below in conjunction with the accompanying drawings and the present invention is described in further detail by embodiment.
Referring to Fig. 1, the embodiment of the present invention can reduce the urea heat of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate
Solution ammonia structure processed includes urea liquid dissolving tank 1, filter 2, urea liquid transfer pump 3, metered dispensing unit 4, atomization spray
Rifle 5, pyrolysis chamber 6, SCR reactors, flue gas heat-exchange unit 11, dilution air 14 and electric heater.
Urea liquid dissolving tank 1, filter 2, urea liquid transfer pump 3, metered dispensing unit 4, atomizing lance 5 are successively
Connection.
Atomizing lance 5 is arranged in pyrolysis chamber 6.
The gas vent at the top of pyrolysis chamber 6 is connected with ammonia-spraying grid 7.
Ammonia-spraying grid 7, static mixer 8, flow straightening grid 9, first floor catalyst 10, are disposed with SCR reactors
Two layers of catalyst 12 and third layer catalyst 13, ammonia-spraying grid 7 is close to the smoke inlet of SCR reactors, third layer catalyst 13
Close to the exhanst gas outlet of SCR reactors.
Filter 2 is two, and two filters 2 are arranged in parallel.
Urea liquid transfer pump 3 is two, and two urea liquid transfer pumps 3 are arranged in parallel.
The outlet of dilution air 14 is connected with the heat transferring medium entrance of flue gas heat-exchange unit 11.Dilution air 14 is two, two
Dilution air 14 is arranged in parallel.
Flue gas heat-exchange unit 11 is arranged between first floor catalyst 10 and second layer catalyst 12, the flue gas of flue gas heat-exchange unit 11
Entrance is communicated with the exhanst gas outlet of first floor catalyst 10, the exhanst gas outlet of flue gas heat-exchange unit 11 and the flue gas of second layer catalyst 12
Entrance is communicated
The outlet of the heat transferring medium of flue gas heat-exchange unit 11 is connected with the gas access of the bottom of pyrolysis chamber 6.
The heat transferring medium of flue gas heat-exchange unit 11 exports and electric heater is provided between the gas access of pyrolysis chamber 6, and advantage is real
In existing routine use based on high-temperature flue gas heat exchanger supplemented by electric heater（Fine setting and quick response）Occupation mode, it is necessary
When both it is standby each other, be conducive to the reliability of raising system.
Flue gas heat-exchange unit 11 uses pipe heat exchanger, and heat exchanger tube uses finned tube, and advantage is can to optimize first floor catalyst
Flue gas flow field between 10 and second layer catalyst 12, is further ensured that the Effec-tive Function of SCR equipment for denitrifying flue gas, reduces ammonia and escapes
Ease amount, can also reduce the generation of ammonium hydrogen sulfate to a certain extent.Flue gas heat-exchange unit 11 is one or more levels.
Metered dispensing unit 4 needs to automatically control the urea amount for spraying into pyrolysis chamber 6 according to system.
It is a kind of to reduce the urea pyrolysis ammonia method of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate：
Flue gas enters from the smoke inlet of SCR reactors；Mass concentration is 30%~50% urea liquid in urea liquid storage tank 1
After being filtered through filter 2, metered dispensing unit 4 is sent into by urea liquid transfer pump 3 and carries out metering distribution, mist is then fed into
Change spray gun 5, atomizing lance 5 injects urea solution into pyrolysis chamber 6, is sufficiently mixed, is pyrolyzed with high-temperature evaporation gas, form ammonia quality
The mixed gas of the ammonia of concentration 5%, air and vapor；Mixed gas enters ammonia-spraying grid by the gas vent at the top of pyrolysis chamber 6
7, mixed gas is injected in the flue gas of SCR reactors by ammonia-spraying grid 7, and mixed gas is mixed by static mixer 8 with flue gas
Enter first floor catalyst 10 after conjunction and carry out reduction reaction；Flue gas after reduction reaction by the temperature of flue gas heat-exchange unit 11 reduction by 20~
Second layer catalyst 12 is sequentially entered after 50 DEG C and third layer catalyst 13 carries out reduction reaction, finally from the cigarette of SCR reactors
Gas outlet discharge.Due to flue-gas temperature reduction, the SO of second layer catalyst 12 and third layer catalyst 132/SO3Conversion ratio drops
It is low, SO3Growing amount reduce, effectively alleviate catalyst and below in equipment ABS deposition, and do not influence equipment for denitrifying flue gas
Full load puts into operation.
Dilution air 14 provides enough diluent gas, and diluent gas enters flue gas heat-exchange unit 11 as heat transferring medium, with
Flue gas in SCR reactors carries out heat exchange, heats diluent gas using fume afterheat, heated diluent gas is again by electricity
Heater is further heated to 350~650 DEG C, subsequently into pyrolysis chamber 6, the boil-off gas as pyrolysis urea liquid, with atomization
The urea liquid particle that spray gun 5 is sprayed into is sufficiently mixed, and urea is decomposed, is prepared reducing agent NH3。
Diluent gas is surrounding air.
In the present embodiment, diluent gas again by electric heater be further heated to 350 DEG C, 400 DEG C, 450 DEG C, 500 DEG C,
550 DEG C, 600 DEG C or 650 DEG C.
In the present embodiment, flue gas after reduction reaction by flue gas heat-exchange unit temperature reduce by 20 DEG C, 25 DEG C, 30 DEG C, 35 DEG C,
40 DEG C, 45 DEG C or 50 DEG C.
Above content described in this specification is only to structure example explanation of the present invention；Moreover, this hair
The title that bright each several part is taken can also be different, what all construction, feature and principles according to described in inventional idea of the present invention were done etc.
In effect or simple change, the protection domain for being included in patent of the present invention.
Claims (10)
1. a kind of reduce the urea pyrolysis ammonia structure of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate, including urea
Solution dissolving tank, filter, urea liquid transfer pump, metered dispensing unit, atomizing lance, pyrolysis chamber and SCR reactors；Urine
Plain solution dissolving tank, filter, urea liquid transfer pump, metered dispensing unit, atomizing lance are sequentially communicated；Atomizing lance is pacified
In pyrolysis chamber；Ammonia-spraying grid, static mixer, flow straightening grid, first floor catalyst, are disposed with SCR reactors
Two layers of catalyst and third layer catalyst；The gas vent of pyrolysis chamber is connected with ammonia-spraying grid；It is characterized in that：Also include flue gas
Heat exchanger, electric heater and dilution air；Flue gas heat-exchange unit is arranged between first floor catalyst and second layer catalyst, and flue gas is changed
The smoke inlet of hot device is communicated with the exhanst gas outlet of first floor catalyst, exhanst gas outlet and the second layer catalyst of flue gas heat-exchange unit
Smoke inlet is communicated；The heat transferring medium outlet of flue gas heat-exchange unit is connected with pyrolysis chamber gas access, heat transferring medium entrance and dilution
The outlet of blower fan；Electric heater is arranged between the outlet of flue gas heat-exchange unit heat transferring medium and pyrolysis chamber gas access.
2. according to claim 1 reduce the urea pyrolysis system of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate
Ammonia structure, it is characterised in that：Described dilution air is two, and two dilution airs are arranged in parallel.
3. according to claim 1 reduce the urea pyrolysis system of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate
Ammonia structure, it is characterised in that：Described flue gas heat-exchange unit uses pipe heat exchanger, and heat exchanger tube uses finned tube.
4. according to claim 1 reduce the urea pyrolysis system of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate
Ammonia structure, it is characterised in that：Described filter is two, and two filters are arranged in parallel.
5. according to claim 1 reduce the urea pyrolysis system of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate
Ammonia structure, it is characterised in that：Described urea liquid transfer pump is two, and two urea liquid transfer pumps are arranged in parallel.
6. a kind of reduce the urea pyrolysis ammonia method of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate, its feature exists
In：Carried out using the urea pyrolysis ammonia structure described in claim 1-5 any claims；Cigarette of the flue gas from SCR reactors
Gas entrance enters；After concentration of polymer solution filters for 30%~50% urea liquid through filter in urea liquid storage tank, lead to
Cross urea liquid supply and be pumped into metered dispensing unit and carry out metering distribution, be then fed into atomizing lance, atomizing lance is by urea
Solution is sprayed into pyrolysis chamber, is sufficiently mixed, is pyrolyzed with the boil-off gas of high temperature, forms the mixed gas of ammonia, air and vapor；It is mixed
Close gas and ammonia-spraying grid is entered by the gas vent of pyrolysis chamber, mixed gas is injected to the flue gas of SCR reactors by ammonia-spraying grid
In, mixed gas enters first floor catalyst after static mixer is mixed with flue gas and carries out reduction reaction；After reduction reaction
Flue gas sequentially enters second layer catalyst and third layer catalyst is gone back after reducing by 20~50 DEG C by flue gas heat-exchange unit temperature
Original reaction, is finally discharged from the exhanst gas outlet of SCR reactors；
Dilution air provides diluent gas, and diluent gas is used as the cigarette in heat transferring medium, with SCR reactors into flue gas heat-exchange unit
Gas carries out heat exchange, and diluent gas is heated using fume afterheat, and heated diluent gas further adds by electric heater again
Heat is to 350~650 DEG C, and subsequently into pyrolysis chamber, the boil-off gas as pyrolysis urea liquid, the urea sprayed into atomizing lance is molten
Liquid particle is sufficiently mixed, and urea is decomposed, and prepares reducing agent NH3。
7. according to claim 6 reduce the urea pyrolysis system of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate
Ammonia method, it is characterised in that：Described diluent gas is surrounding air.
8. according to claim 6 reduce the urea pyrolysis system of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate
Ammonia method, it is characterised in that：Described diluent gas again by electric heater be further heated to 350 DEG C, 400 DEG C, 450 DEG C,
500 DEG C, 550 DEG C, 600 DEG C or 650 DEG C.
9. according to claim 6 reduce the urea pyrolysis system of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate
Ammonia method, it is characterised in that：Flue gas after reduction reaction by flue gas heat-exchange unit temperature reduce by 20 DEG C, 25 DEG C, 30 DEG C, 35 DEG C,
40 DEG C, 45 DEG C or 50 DEG C.
10. according to claim 6 reduce the urea pyrolysis of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate
Ammonia method processed, it is characterised in that：Described metered dispensing unit controls to spray into the urea amount of pyrolysis chamber as needed.
Priority Applications (1)
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